Combustion burners are used in the metal melting of iron and the like, in the manufacture of glass, in the incineration of waste, and the like. As methods that heat or melt a target object such as metal, glass, waste, or the like, using a combustion burner, there are methods that heat or melt through direct application of flame to a target object, and there are methods that heat or melt a target object indirectly using the radiant heat of flame.
In comparison with methods that heat or melt a target object indirectly using the radiant heat of flame, methods that heat or melt through direct application of flame to a target object have an advantage in that the efficiency of utilization of energy is high.
Given that, in a case in which the target object for which heating or melting is desired is a powder (a raw material powder), since the surface area per unit volume of the target object is large, it is possible to heat or melt the target object efficiently by passing the target object through the flame and/or a high temperature region in the vicinity of the flame (hereinafter, referred to as a “flame region”).
Patent Documents 1 to 4 disclose combustion burners and burning methods that heat or melt by installing a powder-spouting nozzle, from which powder is spouted, in a combustion burner or in the vicinity of a combustion burner; and directly inserting the powder into the flame region while simultaneously spouting the powder.
The combustion burners that are disclosed in Patent Documents 1 and 2 have a structure that includes a raw material powder outlet which is disposed in the center of a leading end of the combustion burner, and spouts a raw material powder, a fuel outlet which is disposed in the periphery of the raw material powder outlet, and spouts fuel, and an oxygen outlet which is disposed in the periphery of the raw material powder outlet, and spouts oxygen.
The combustion burner that is disclosed in Patent Document 3 has a structure that includes a dispersal gas outlet that spouts a dispersal gas dispersing a raw material powder into the center of a leading end of the combustion burner, and a raw material powder outlet which is disposed in the vicinity of the dispersal gas outlets, and spouts the raw material powder.
The combustion burner that is disclosed in Patent Document 4 has a structure in which nozzles on a leading end surface are arranged concentrically as a whole from a central section toward an outer section in an order of a fuel supply nozzle, a primary combustion gas supply nozzle, a target process object supply nozzle, and a secondary combustion gas supply nozzle, and a leading end of the primary combustion gas supply nozzles is opened in a circular shape that surrounds a leading end opening section of the fuel supply nozzles, an oxygen enrich gas is used as a primary combustion gas and a secondary combustion gas, and only incinerator fly ash, or a mixture of incinerator fly ash and glass for basicity adjustment is used as the target object.